Cable insulation material with low by-products of anti-scorching and its preparation method and cable

Abstract

The present application provides a cable insulation material with low by-product and anti-scorching property, a preparation method thereof and a cable. The cable insulation material comprises, by weight: low density polyethylene: 80-100 parts; nucleating agent: 0.1-5 parts; antioxidant: 0.1-0.4 parts; crosslinking agent: 1.0-1.9 parts; co-crosslinking agent: 0-0.4 parts; molecular weight regulator: 0.2-1.0 parts. The cable insulation material has improved anti-scorching property, reduced crosslinking by-product and improved insulation performance. The preparation method of the cable insulation material is simple and easy to operate, raw materials are easy to obtain, and is suitable for mass production.

Description

TECHNICAL FIELD

[0001] The present application relates to a cable insulation material with low by-product of anti-scorch property and its preparation method and cable, belonging to the technical field of cable materials. BACKGROUND

[0002] With the rapid development of power grid construction, the demand for 500kV voltage grade AC / DC cable of power transmission project is gradually increasing, which also puts forward higher requirements for cable insulation materials. At present, the cross-linked polyethylene (XLPE) cable insulation material of 220kV and below has the shortcomings of poor anti-scorch property and high content of cross-linking by-products, which limits its application in higher voltage grade AC / DC cable.

[0003] At present, the formula system of high-voltage cable insulation material is low-density polyethylene, antioxidant and cross-linking agent. The most commonly used antioxidant is 4,4'-thiobis(6-tert-butyl-3-methylphenol), commonly known as No. 300, and the most commonly used cross-linking agent is dicumyl peroxide, simply referred to as DCP.

[0004] Scorching refers to the phenomenon that the cable insulation material is pre-crosslinked during processing, the melt viscosity rises and forms coking. The coking affects the continuous extrusion operation and the safety of cable operation. Antioxidant 300 has the dual role of capturing oxygen free radicals and decomposing hydroperoxide, and has excellent antioxidant effect. However, there is a contradictory effect between it and DCP, which leads to an increase in the addition amount of dicumyl peroxide, an increase in the cross-linking rate, and an increase in the probability of scorching of the cable insulation material during extrusion processing.

[0005] In addition, DCP produces by-products such as acetophenone, alpha-methyl styrene, and cumyl alcohol, which are difficult to remove as the thickness of the insulation layer increases, affecting the insulation performance on the one hand and prolonging the cable degassing time on the other hand. The addition of antioxidant 300 increases the addition amount of DCP, and the content of cross-linking by-products also increases accordingly.

[0006] In order to improve the anti-scorch property of the cable insulation material and reduce the cross-linking by-products, the existing technology usually uses the way of compounding antioxidants and adding auxiliary cross-linking agents such as triallyl isocyanurate (TAIC) and liquid polybutadiene (LPB) to optimize the antioxidant cross-linking system, but the improvement effect is not obvious and new problems are brought, such as uneven cross-linking caused by excessive addition of TAIC and LPB, unstable heat extension results, and decreased mechanical properties.

[0007] Therefore, how to provide a high-voltage cable insulation material with anti-scorch property and low cross-linking by-products is a problem that those skilled in the art need to solve. SUMMARY

[0008] Problems to be solved by the application

[0009] In view of the technical problems existing in the prior art, the present application provides a cable insulation material. The cable insulation material of the present application has improved scorch resistance, reduced crosslinking by-products, and improved insulation performance.

[0010] Further, the present application provides a preparation method of the cable insulation material. The preparation method of the present application is simple and easy to implement, raw materials are easy to obtain, and is suitable for mass production.

[0011] Solution for solving the problem

[0012] The present application provides a cable insulation material, comprising, by weight:

[0013] Low-density polyethylene: 80-100 parts;

[0014] Nucleating agent: 0.1-5 parts;

[0015] Antioxidant: 0.1-0.4 parts;

[0016] Crosslinking agent: 1.0-1.9 parts;

[0017] Co-crosslinking agent: 0-0.4 parts;

[0018] Molecular weight regulator: 0.2-1.0 parts.

[0019] According to the cable insulation material of the present application, the density of the low-density polyethylene is 0.912-0.932 g / cm 3 ; and the melt flow rate of the low-density polyethylene under the condition of 190℃, 2.16 kg is 1.8-2.2 g / 10 min.

[0020] According to the cable insulation material of the present application, the nucleating agent comprises one or more than two combinations of high-density polyethylene, nano-silicon dioxide, and bis(3,4-dimethylbenzyl) sorbitol.

[0021] According to the cable insulation material of the present application, the density of the high-density polyethylene is 0.940-0.976 g / cm 3 ; and the melt flow rate of the high-density polyethylene under the condition of 190℃, 2.16 kg is 6.5-10.0 g / 10 min.

[0022] According to the cable insulation material of the present application, the crosslinking agent comprises a peroxide crosslinking agent, preferably comprises one or more than two combinations of benzoyl peroxide, dicumyl peroxide, and bis-tert-butyl peroxide diisopropyl benzene;

[0023] The antioxidant includes one or more than two combinations of 2,2'-thiobis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tetra[β-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate] pentaerythritol ester, and 4,4'-thiobis(6-tert-butyl-3-methylphenol).

[0024] The cable insulation material according to the present application, wherein the co-crosslinking agent includes liquid polybutadiene and / or triallyl isocyanurate.

[0025] The molecular weight regulator includes 2,4-diphenyl-4-methyl-1-pentene.

[0026] The present application also provides a preparation method of the cable insulation material according to the present application, which includes the steps of mixing and extruding, and granulating the components of the cable insulation material.

[0027] The preparation method according to the present application includes the following steps:

[0028] After mixing the low-density polyethylene, the nucleating agent, the antioxidant, and the co-crosslinking agent, the intermediate material is obtained by extrusion and granulation;

[0029] After mixing the intermediate material with the crosslinking agent and the molecular weight regulator, the cable insulation material is obtained by post-absorption.

[0030] The preparation method according to the present application, wherein the mixing, extrusion, and granulation are performed by using a double-screw extruder; preferably, the rotation speed of the double-screw extruder is 200 rpm-400 rpm, and the temperature of the mixing is 85-205℃.

[0031] The temperature of the post-absorption is 60℃-80℃, and the post-absorption time is 16-24h.

[0032] The present application also provides a cable including the cable insulation material according to the present application.

[0033] Effects of the present application

[0034] The cable insulation material of the present application has improved anti-scorching property, reduced crosslinking by-products, and improved insulation performance.

[0035] The preparation method of the cable insulation material of the present application is simple and easy to implement, the raw materials are easy to obtain, and is suitable for mass production. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 Fitting curve diagrams of rheological experiments of the cable insulation materials of Examples 1-11 and Comparative Examples 1-7 are shown.

[0037] Figure 2A schematic diagram of the Weibull distribution of cable insulation material in Examples 1-11 is shown;

[0038] Figure 3 The diagram shows the Weibull distribution of cable insulation material in Comparative Examples 1-7. Detailed Implementation

[0039] Various exemplary embodiments, features, and aspects of the present invention will be described in detail below. The term "exemplary" as used herein means "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior to or better than other embodiments.

[0040] Furthermore, to better illustrate the present invention, numerous specific details are set forth in the following detailed embodiments. Those skilled in the art should understand that the present invention can be practiced without certain specific details. In other instances, methods, means, apparatus, and steps well known to those skilled in the art have not been described in detail in order to highlight the spirit of the present invention.

[0041] Unless otherwise stated, all units used in this specification are international standard units, and all numerical values ​​and ranges appearing in this invention should be understood to include systematic errors that are unavoidable in industrial production.

[0042] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0043] In this specification, references to "some specific / preferred embodiments," "other specific / preferred embodiments," "implementation," etc., refer to specific elements (e.g., features, structures, properties, and / or characteristics) related to that embodiment, which are included in at least one of the embodiments described herein and may or may not be present in other embodiments. Furthermore, it should be understood that these elements may be combined in any suitable manner in various embodiments.

[0044] In this specification, the range of values ​​referred to as "value A to value B" refers to the range including the endpoint values ​​A and B.

[0045] In this instruction manual, when "room temperature" or "room temperature" is used, the temperature can be 10-25℃.

[0046] <First aspect>

[0047] A first aspect of the present invention provides a cable insulation material, comprising, by weight:

[0048] Low-density polyethylene: 80-100 parts;

[0049] Nucleating agent: 0.1-5 parts;

[0050] Antioxidant: 0.1-0.4 parts;

[0051] Crosslinking agent: 1.0-1.9 parts;

[0052] Co-crosslinking agent: 0-0.4 parts;

[0053] Molecular weight regulator: 0.2-1.0 parts.

[0054] The cable insulation material of the present application has improved anti-scorching property, reduced crosslinking by-products, and improved insulation performance.

[0055] Low density polyethylene

[0056] In the present application, low density polyethylene is used as the base material. In the present application, the content of low density polyethylene is 80-100 parts by weight, for example: 82 parts, 85 parts, 88 parts, 90 parts, 92 parts, 95 parts, 98 parts, etc.

[0057] Specifically, in the present application, the density of the low density polyethylene is 0.912-0.932 g / cm 3 ; the melt flow rate of the low density polyethylene under the condition of 190℃, 2.16 kg is 1.8-2.2 g / 10 min.

[0058] Nucleating agent

[0059] The present application improves the electrical strength and electrical reliability of the cable insulation material by using a nucleating agent.

[0060] When the content of the nucleating agent is less than 0.1 parts by weight, it is not sufficient to improve the electrical strength of the cable insulation material; when the content of the nucleating agent is more than 5 parts, the electrical strength of the cable insulation material cannot be further improved, and it is not conducive to later processing. Specifically, in the present application, the nucleating agent includes one or a combination of two or more of high density polyethylene, nano-silicon dioxide, and bis(3,4-dimethylbenzyl)sorbitol. Therefore, in the present application, the content of the nucleating agent is 0.1-5 parts by weight, for example: 0.8 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, etc.

[0061] Further, the density of the high density polyethylene is 0.940-0.976 g / cm 3 ; the melt flow rate of the high density polyethylene under the condition of 190℃, 2.16 kg is 6.5-10.0 g / 10 min.

[0062] Antioxidant

[0063] The present application improves the anti-aging performance of the cable insulation material of the present application by using an antioxidant. In the present application, the content of the antioxidant is 0.1-0.4 parts by weight, for example, 0.2 parts, 0.3 parts, etc. When the content of the antioxidant is 0.1-0.4 parts, the anti-aging performance is excellent.

[0064] Specifically, in the present application, the antioxidant includes one or a combination of two or more of 2,2'-thiobis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tetra[β-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate] pentaerythritol ester, and 4,4'-thiobis(6-tert-butyl-3-methylphenol).

[0065] Crosslinking agent

[0066] The present application produces cross-linking of the cable insulation material by using a cross-linking agent. Specifically, in the present application, the content of the cross-linking agent is 1.0-1.9 parts by weight, for example, 1.2 parts, 1.5 parts, 1.7 parts, etc. When the content of the cross-linking agent is 1.0-1.9 parts, effective cross-linking of the cable insulation material can be achieved.

[0067] Specifically, in the present application, the cross-linking agent includes a peroxide cross-linking agent. Preferably, the peroxide cross-linking agent includes one or a combination of two or more of benzoyl peroxide, dicumyl peroxide (DCP), bis-tert-butyl peroxydiisopropylbenzene (BIPB), etc.

[0068] Co-crosslinking agent

[0069] The inventors of the present application found that the use of a co-cross-linking agent can reduce the amount of cross-linking agent, improve the anti-scorching property, reduce the cross-linking by-products, and ensure the cross-linking degree. Therefore, the present application can appropriately add some co-cross-linking agents when necessary. In the present application, the content of the co-cross-linking agent can be 0-0.4 parts by weight, for example, 0.1 parts, 0.15 parts, 0.25 parts, 0.3 parts, 0.35 parts, etc. However, too high a co-cross-linking agent will result in a large loss of mechanical properties, which cannot meet the requirements of cable materials.

[0070] Specifically, in the present application, the co-cross-linking agent includes liquid polybutadiene and / or triallyl isocyanurate.

[0071] Molecular regulator

[0072] The application innovatively uses a molecular weight regulator, proposes a new crosslinking system against oxidation, reduces the amount of crosslinking agent, effectively improves the poor anti-scorching property and high content of crosslinking by-products, and is suitable for the current high-temperature extrusion and post-absorption method of high-voltage insulation material, avoids the problem of uneven crosslinking, and provides a new technical idea for improving the anti-scorching property and reducing the crosslinking by-products of high-voltage insulation material.

[0073] Specifically, in the application, the content of the molecular weight regulator is 0.2-1.0 parts by weight. When the content of the molecular weight regulator is 0.2-1.0 parts, the amount of crosslinking agent can be effectively reduced, the anti-scorching property can be improved, and the crosslinking by-products can be reduced. When the content of the molecular weight regulator is less than 0.2 parts, its effect is not obvious, and when the content of the molecular weight regulator is more than 1.0 parts, a more excellent effect cannot be achieved.

[0074] Specifically, in the application, the molecular weight regulator comprises 2,4-diphenyl-4-methyl-1-pentene.

[0075] <Second aspect>

[0076] The second aspect of the application provides a preparation method of the cable insulation material according to the first aspect of the application, which comprises the steps of mixing and extruding, and granulating the components of the cable insulation material.

[0077] Specifically, the preparation method of the application comprises the following steps:

[0078] After the low-density polyethylene, the nucleating agent, the antioxidant and the auxiliary crosslinking agent are mixed and kneaded, they are extruded and granulated to obtain an intermediate material;

[0079] After the intermediate material is mixed with the crosslinking agent and the molecular weight regulator, post-absorption is performed to obtain the cable insulation material.

[0080] Specifically, the application preferably uses a double-screw extruder for mixing, extruding and granulating; preferably, the rotating speed of the double-screw extruder is 200 rpm-400 rpm, and the mixing temperature is 85-205℃.

[0081] The post-absorption temperature is 60℃-80℃, and the post-absorption time is 16-24h.

[0082] In some specific embodiments, the preparation method comprises:

[0083] The low-density polyethylene, nucleating agent, antioxidant are mixed by a metering scale metering system, and then automatically added into a double-screw extruder, the temperature of the feeding port is controlled below 100℃, the auxiliary cross-linking agent is added into the double-screw extruder by a liquid scale, the screw rotating speed is 200rpm-400rpm, the temperature of the mixing is 85-205℃; specifically, the temperature of each zone of the double-screw extruder is 85℃-105℃, 110℃-130℃, 125℃-140℃, 135℃-150℃, 145℃-160℃, 155℃-175℃, 170℃-185℃, 180℃-195℃, 180℃-200℃, 180℃-200℃, after mixing, homogenizing, filtering, extruding and granulating, an intermediate material is obtained;

[0084] The intermediate material is heated to 60℃-80℃, the cross-linking agent and the molecular weight regulator are added and uniformly mixed, and then post-absorption is carried out, the post-absorption temperature is 60℃-80℃, and the absorption time is 16-24h, so as to obtain a cable insulation material with anti-scorching and low by-products.

[0085] <Third aspect>

[0086] The third aspect of the present application provides a cable comprising the cable insulation material with anti-scorching and low by-products according to the present application.

[0087] Embodiment

[0088] The embodiments of the present application will be described in detail below with reference to the examples, but those skilled in the art will understand that the following examples are only used to illustrate the present application, and should not be regarded as limiting the scope of the present application. If the specific conditions are not indicated in the examples, the conventional conditions or the conditions recommended by the manufacturer are used. If the manufacturers of the reagents or instruments are not indicated, they are all conventional products that can be obtained by market purchase.

[0089] Example 1

[0090] Take 100 parts by weight of low density polyethylene, 0.2 parts by weight of antioxidant and 0.5 parts by weight of nucleating agent through the metering scale metering system mixed after automatic adding double screw extruder, the temperature of the discharge port is controlled below 100℃, 0.2 parts by weight of crosslinking agent is put into the double screw through the liquid scale. Set the screw speed to 200 rpm, the temperature of each zone of the double screw body is 100℃, 125℃, 135℃, 145℃, 155℃, 170℃, 180℃, 190℃, 195℃, 195℃, after mixing, homogenizing, filtering, extruding, granulating to get the intermediate material. Among them, the melt flow rate of the low density polyethylene is 1.9g / 10min(190℃, 2.16kg); antioxidant is 4,4'-thio bis(6-tert-butyl-3-methyl phenol); crosslinking agent is liquid polybutadiene; nucleating agent is high density polyethylene, the melt flow rate is 7g / 10min(190℃, 2.16kg).

[0091] Heat the intermediate material to 70℃, add 1.5 parts by weight of crosslinking agent and 0.2 parts by weight of molecular weight regulator to mix evenly, and then perform post-absorption. The crosslinking agent is dicumyl peroxide, the molecular weight regulator is 2,4-diphenyl-4-methyl-1-pentene, the post-absorption temperature is 70℃, and the absorption time is 16h to obtain a cable insulation material.

[0092] Example 2

[0093] Take 100 parts by weight of low density polyethylene, 0.2 parts by weight of antioxidant and 0.5 parts by weight of nucleating agent through the metering scale metering system mixed after automatic adding double screw extruder, the temperature of the discharge port is controlled below 100℃, 0.2 parts by weight of crosslinking agent is put into the double screw through the liquid scale. Set the screw speed to 200 rpm, the temperature of each zone of the double screw body is 100℃, 125℃, 135℃, 145℃, 155℃, 170℃, 180℃, 190℃, 195℃, 195℃, after mixing, homogenizing, filtering, extruding, granulating to get the intermediate material. Among them, the melt flow rate of the low density polyethylene is 1.9g / 10min(190℃, 2.16kg); antioxidant is 4,4'-thio bis(6-tert-butyl-3-methyl phenol); crosslinking agent is liquid polybutadiene; nucleating agent is high density polyethylene, the melt flow rate is 7g / 10min(190℃, 2.16kg).

[0094] Heat the intermediate material to 70℃, add 1.5 parts by weight of crosslinking agent and 0.2 parts by weight of molecular weight regulator to mix evenly, and then perform post-absorption. Among them, the crosslinking agent is dicumyl peroxide, the molecular weight regulator is 2,4-diphenyl-4-methyl-1-pentene, the post-absorption temperature is 70℃, and the absorption time is 16h to obtain a cable insulation material.

[0095] Example 3

[0096] 100 parts by weight of low density polyethylene, 0.2 parts by weight of antioxidant and 0.5 parts by weight of nucleating agent were mixed by a metering scale metering system and then automatically added into a twin-screw extruder, the temperature of the feeding port was controlled below 100℃, 0.2 parts by weight of crosslinking aid was added into the twin-screw extruder by a liquid scale, the rotation speed of the screw was set to 200 rpm, the temperature of each zone of the twin-screw extruder was set to 100℃, 125℃, 135℃, 145℃, 155℃, 170℃, 180℃, 190℃, 195℃, 195℃, and then the intermediate material was obtained by mixing, homogenizing, filtering, extruding and granulating. The melt flow rate of the low density polyethylene was 1.9 g / 10 min (190℃, 2.16 kg), the antioxidant was 2,2'-thiobis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], the crosslinking aid was triallyl isocyanurate, and the nucleating agent was high density polyethylene with a melt flow rate of 7 g / 10 min (190℃, 2.16 kg).

[0097] The intermediate material was heated to 70℃, 1.3 parts by weight of crosslinking agent and 0.2 parts by weight of molecular weight regulator were added and uniformly mixed, and then post-absorption was performed. The crosslinking agent was dicumyl peroxide, the molecular weight regulator was 2,4-diphenyl-4-methyl-1-pentene, the post-absorption temperature was 70℃, and the absorption time was 16 h, and then the cable insulation material was obtained.

[0098] Example 4

[0099] 100 parts by weight of low density polyethylene, 0.2 parts by weight of antioxidant and 0.5 parts by weight of nucleating agent were mixed by a metering scale metering system and then automatically added into a twin-screw extruder, the temperature of the feeding port was controlled below 100℃, 0.2 parts by weight of crosslinking aid was added into the twin-screw extruder by a liquid scale, the rotation speed of the screw was set to 200 rpm, the temperature of each zone of the twin-screw extruder was set to 100℃, 125℃, 135℃, 145℃, 155℃, 170℃, 180℃, 190℃, 195℃, 195℃, and then the intermediate material was obtained by mixing, homogenizing, filtering, extruding and granulating. The melt flow rate of the low density polyethylene was 1.9 g / 10 min (190℃, 2.16 kg), the antioxidant was 2,2'-thiobis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], the crosslinking aid was triallyl isocyanurate, and the nucleating agent was nano-silicon dioxide.

[0100] The intermediate material is heated to 70°C, 1.3 parts by weight of a crosslinking agent mixed with 0.2 parts by weight of a molecular weight regulator is added and uniformly mixed, and post-absorption is carried out. The crosslinking agent is dicumyl peroxide, the molecular weight regulator is 2,4-diphenyl-4-methyl-1-pentene, the post-absorption temperature is 70°C, and the absorption time is 16h, to obtain a cable insulation material.

[0101] Example 5

[0102] 100 parts by weight of low-density polyethylene, 0.2 parts by weight of an antioxidant, and 1 part by weight of a nucleating agent are mixed by a metering scale metering system and then automatically added to a twin-screw extruder, with the temperature of the discharge port controlled below 100°C. 0.2 parts by weight of a crosslinking aid is added to the twin-screw extruder through a liquid scale. The screw rotation speed is set to 200 rpm, and the temperature of each zone of the twin-screw body is 100°C, 125°C, 135°C, 145°C, 155°C, 170°C, 180°C, 190°C, 195°C, and 195°C. After mixing, homogenizing, filtering, extruding, and granulating, an intermediate material is obtained. The low-density polyethylene has a melt flow rate of 1.9g / 10min (190°C, 2.16kg); the antioxidant is 4,4'-thiobis(6-tert-butyl-3-methylphenol); the crosslinking aid is liquid polybutadiene; and the nucleating agent is high-density polyethylene with a melt flow rate of 7g / 10min (190°C, 2.16kg).

[0103] The intermediate material is heated to 70°C, 1.5 parts by weight of a crosslinking agent mixed with 0.2 parts by weight of a molecular weight regulator is added and uniformly mixed, and post-absorption is carried out. The crosslinking agent is dicumyl peroxide, the molecular weight regulator is 2,4-diphenyl-4-methyl-1-pentene, the post-absorption temperature is 70°C, and the absorption time is 16h, to obtain a cable insulation material.

[0104] Example 6

[0105] Take 100 parts by weight of low density polyethylene, 0.2 parts by weight of antioxidant and 0.5 parts by weight of nucleating agent through the metering scale metering system mixed after automatic adding double screw extruder, the temperature of the discharge port is controlled below 100℃, 0.3 parts by weight of crosslinking agent is put into the double screw through the liquid scale. Set the screw speed to 200 rpm, the temperature of each zone of the double screw body is 100℃, 125℃, 135℃, 145℃, 155℃, 170℃, 180℃, 190℃, 195℃, 195℃, after mixing, homogenizing, filtering, extruding, granulating to get the intermediate material. Among them, the melt flow rate of the low density polyethylene is 1.9g / 10min(190℃, 2.16kg); antioxidant is 4,4'-thio bis(6-tert-butyl-3-methyl phenol); crosslinking agent is liquid polybutadiene; nucleating agent is high density polyethylene, the melt flow rate is 7g / 10min(190℃, 2.16kg).

[0106] Heat the intermediate material to 70℃, add 1.4 parts by weight of crosslinking agent and 0.2 parts by weight of molecular weight regulator to mix evenly, and then perform post-absorption. Among them, the crosslinking agent is dicumyl peroxide, the molecular weight regulator is 2,4-diphenyl-4-methyl-1-pentene, the post-absorption temperature is 70℃, the absorption time is 16h, to get the cable insulation material.

[0107] Example 7

[0108] Take 100 parts by weight of low density polyethylene, 0.2 parts by weight of antioxidant and 0.5 parts by weight of nucleating agent through the metering scale metering system mixed after automatic adding double screw extruder, the temperature of the discharge port is controlled below 100℃, 0.3 parts by weight of crosslinking agent is put into the double screw through the liquid scale. Set the screw speed to 200 rpm, the temperature of each zone of the double screw body is 100℃, 125℃, 135℃, 145℃, 155℃, 170℃, 180℃, 190℃, 195℃, 195℃, after mixing, homogenizing, filtering, extruding, granulating to get the intermediate material. Among them, the melt flow rate of the low density polyethylene is 1.9g / 10min(190℃, 2.16kg); antioxidant is 4,4'-thio bis(6-tert-butyl-3-methyl phenol); crosslinking agent is liquid polybutadiene; nucleating agent is high density polyethylene, the melt flow rate is 7g / 10min(190℃, 2.16kg).

[0109] Heat the intermediate material to 70℃, add 1.4 parts by weight of crosslinking agent and 0.2 parts by weight of molecular weight regulator to mix evenly, and then perform post-absorption. Among them, the crosslinking agent is dicumyl peroxide, the molecular weight regulator is 2,4-diphenyl-4-methyl-1-pentene, the post-absorption temperature is 70℃, the absorption time is 16h, to get the cable insulation material.

[0110] Example 8

[0111] 100 parts by weight of low density polyethylene, 0.2 parts by weight of antioxidant and 0.5 parts by weight of nucleating agent were mixed by a metering scale metering system and then automatically added into a twin-screw extruder, the temperature of the feeding port was controlled below 100℃, 0.2 parts by weight of crosslinking aid was added into the twin-screw extruder by a liquid scale. The screw rotation speed was set to 300 rpm, the temperature of each zone of the twin-screw extruder was 90℃, 115℃, 130℃, 140℃, 155℃, 165℃, 175℃, 185℃, 185℃, 185℃, and the intermediate material was obtained by mixing, homogenizing, filtering, extruding and granulating. The melt flow rate of the low density polyethylene was 1.9 g / 10 min (190℃, 2.16 kg), the antioxidant was tetra[β-(3',5'-di-tert-butyl-4'-hydroxyphenyl) propionic acid] pentaerythritol ester, the crosslinking aid was liquid polybutadiene, and the nucleating agent was high density polyethylene with a melt flow rate of 7 g / 10 min (190℃, 2.16 kg).

[0112] The intermediate material was heated to 70℃, 1.3 parts by weight of crosslinking agent and 0.2 parts by weight of molecular weight regulator were added and uniformly mixed, and post-absorption was carried out. The crosslinking agent was dicumyl peroxide, the molecular weight regulator was 2,4-diphenyl-4-methyl-1-pentene, the post-absorption temperature was 70℃, and the absorption time was 16 h, and the cable insulation material was obtained.

[0113] Example 9

[0114] 100 parts by weight of low density polyethylene, 0.2 parts by weight of antioxidant and 0.5 parts by weight of nucleating agent were mixed by a metering scale metering system and then automatically added into a twin-screw extruder, the temperature of the feeding port was controlled below 100℃, 0.2 parts by weight of crosslinking aid was added into the twin-screw extruder by a liquid scale. The screw rotation speed was set to 300 rpm, the temperature of each zone of the twin-screw extruder was 90℃, 115℃, 130℃, 140℃, 155℃, 165℃, 175℃, 185℃, 185℃, 185℃, and the intermediate material was obtained by mixing, homogenizing, filtering, extruding and granulating. The melt flow rate of the low density polyethylene was 1.9 g / 10 min (190℃, 2.16 kg), the antioxidant was tetra[β-(3',5'-di-tert-butyl-4'-hydroxyphenyl) propionic acid] pentaerythritol ester, the crosslinking aid was liquid polybutadiene, and the nucleating agent was high density polyethylene with a melt flow rate of 7 g / 10 min (190℃, 2.16 kg).

[0115] The intermediate material is heated to 70℃, 1.1 parts by weight of crosslinking agent mixed with 0.4 parts by weight of molecular weight regulator is added and uniformly mixed, and post-absorption is carried out. The crosslinking agent is dicumyl peroxide, the molecular weight regulator is 2,4-diphenyl-4-methyl-1-pentene, the post-absorption temperature is 70℃, the absorption time is 16h, and the cable insulation material is obtained.

[0116] Example 10

[0117] 100 parts by weight of low-density polyethylene, 0.2 parts by weight of antioxidant, and 0.5 parts by weight of nucleating agent are mixed by a metering scale metering system and then automatically added to a double screw extruder, the temperature of the discharge port is controlled below 100℃, and 0.3 parts by weight of a crosslinking aid is added to the double screw extruder by a liquid scale. The screw speed is set to 300 rpm, and the temperature of each zone of the double screw extruder is 90℃, 115℃, 130℃, 140℃, 155℃, 165℃, 175℃, 185℃, 185℃, and 185℃. After mixing, homogenizing, filtering, extruding, and granulating, the intermediate material is obtained. The melt flow rate of the low-density polyethylene is 1.9g / 10min (190℃, 2.16kg); the antioxidant is tetra[β-(3',5'-di-tert-butyl-4'-hydroxyphenyl) propionic acid] pentaerythritol ester; the crosslinking aid is liquid polybutadiene; and the nucleating agent is high-density polyethylene with a melt flow rate of 7g / 10min (190℃, 2.16kg).

[0118] The intermediate material is heated to 70℃, 1.0 parts by weight of crosslinking agent mixed with 0.4 parts by weight of molecular weight regulator is added and uniformly mixed, and post-absorption is carried out. The crosslinking agent is dicumyl peroxide, the molecular weight regulator is 2,4-diphenyl-4-methyl-1-pentene, the post-absorption temperature is 70℃, the absorption time is 16h, and the cable insulation material is obtained.

[0119] Example 11

[0120] Take 100 parts by weight of low density polyethylene, 0.2 parts by weight of antioxidant and 1 part by weight of nucleating agent by metering scale metering system mixed after automatic adding into double screw extruder, the temperature of the discharge port is controlled below 100℃, 0.3 parts by weight of crosslinking agent is added into the double screw by liquid scale. Set the screw speed to 300 rpm, the temperature of each zone of the double screw body is 90℃, 115℃, 130℃, 140℃, 155℃, 165℃, 175℃, 185℃, 185℃, 185℃, after mixing, homogenizing, filtering, extruding, granulating, the intermediate material is obtained. The melt flow rate of the low density polyethylene is 1.9g / 10min(190℃, 2.16kg); the antioxidant is tetra[β-(3',5'-di-tert-butyl-4'-hydroxyphenyl) propionic acid] pentaerythritol ester; the crosslinking agent is liquid polybutadiene; the nucleating agent is high density polyethylene, the melt flow rate is 7g / 10min(190℃, 2.16kg).

[0121] The intermediate material is heated to 70℃, 1.0 parts by weight of crosslinking agent and 0.4 parts by weight of molecular weight regulator are added and uniformly mixed, and post-absorption is carried out. The crosslinking agent is dicumyl peroxide, the molecular weight regulator is 2,4-diphenyl-4-methyl-1-pentene, the post-absorption temperature is 70℃, and the absorption time is 16h, to obtain a cable insulation material.

[0122] Comparative Example 1

[0123] Take 100 parts by weight of low density polyethylene, 0.2 parts by weight of antioxidant by metering scale metering system mixed after automatic adding into double screw extruder, the temperature of the discharge port is controlled below 100℃. Set the screw speed to 200 rpm, the temperature of each zone of the double screw body is 100℃, 125℃, 135℃, 145℃, 155℃, 170℃, 180℃, 190℃, 195℃, 195℃, after mixing, homogenizing, filtering, extruding, granulating, the intermediate material is obtained. The melt flow rate of the low density polyethylene is 1.9g / 10min(190℃, 2.16kg); the antioxidant is 4,4'-thiobis(6-tert-butyl-3-methylphenol).

[0124] The intermediate material is heated to 70℃, 1.9 parts by weight of crosslinking agent is added and post-absorption is carried out. The crosslinking agent is dicumyl peroxide, the post-absorption temperature is 70℃, and the absorption time is 16h, to obtain a cable insulation material.

[0125] Comparative Example 2

[0126] Take 100 parts by weight of low density polyethylene, 0.2 parts by weight of antioxidant and 0.5 parts by weight of nucleating agent through the metering scale metering system mixed after automatic adding into the double screw extruder, the temperature of the discharge port is controlled below 100℃, 0.6 parts by weight of crosslinking agent is put into the double screw through the liquid scale, the screw speed is set to 200rpm, the temperature of each zone of the double screw body is 100℃, 125℃, 135℃, 145℃, 155℃, 170℃, 180℃, 190℃, 195℃, 195℃, after mixing, homogenizing, filtering, extruding and granulating, the intermediate material is obtained. Among them, the melt flow rate of the low density polyethylene is 1.9g / 10min(190℃, 2.16kg); the antioxidant is 4,4'-thiobis(6-tert-butyl-3-methylphenol).

[0127] The intermediate material is heated to 70℃, 1.1 parts by weight of crosslinking agent and 0.2 parts by weight of molecular weight regulator are added and uniformly mixed, and post-absorption is carried out. Among them, the crosslinking agent is dicumyl peroxide, the molecular weight regulator is 2,4-diphenyl-4-methyl-1-pentene, the post-absorption temperature is 70℃, and the absorption time is 16h, to obtain a cable insulation material.

[0128] Comparative Example 3

[0129] Take 100 parts by weight of low density polyethylene, 0.2 parts by weight of antioxidant and 6 parts by weight of nucleating agent through the metering scale metering system mixed after automatic adding into the double screw extruder, the temperature of the discharge port is controlled below 100℃, 0.2 parts by weight of crosslinking agent is put into the double screw through the liquid scale. The screw speed is set to 200rpm, the temperature of each zone of the double screw body is 100℃, 125℃, 135℃, 145℃, 155℃, 170℃, 180℃, 190℃, 195℃, 195℃, after mixing, homogenizing, filtering, extruding and granulating, the intermediate material is obtained. Among them, the melt flow rate of the low density polyethylene is 1.9g / 10min(190℃, 2.16kg); the antioxidant is 2,2'-thiobis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; the crosslinking agent is liquid polybutadiene; the nucleating agent is high density polyethylene with a melt flow rate of 7g / 10min(190℃, 2.16kg).

[0130] The intermediate material is heated to 70℃, 1.3 parts by weight of crosslinking agent and 0.2 parts by weight of molecular weight regulator are added and uniformly mixed, and post-absorption is carried out. Among them, the crosslinking agent is dicumyl peroxide, the molecular weight regulator is 2,4-diphenyl-4-methyl-1-pentene, the post-absorption temperature is 70℃, and the absorption time is 16h, to obtain a cable insulation material.

[0131] Comparative Example 4

[0132] Take 100 parts by weight of low density polyethylene, 0.2 parts by weight of antioxidant and 0.05 parts by weight of nucleating agent through the metering scale metering system mixed after automatic adding into double screw extruder, the temperature of the discharge port is controlled below 100℃, 0.2 parts by weight of crosslinking agent is put into the double screw through the liquid scale, the screw speed is set to 200rpm, the temperature of each zone of the double screw body is 100℃, 125℃, 135℃, 145℃, 155℃, 170℃, 180℃, 190℃, 195℃, 195℃, after mixing, homogenizing, filtering, extruding and granulating, the intermediate material is obtained. The melt flow rate of the low density polyethylene is 1.9g / 10min(190℃, 2.16kg); the antioxidant is 2,2'-thiobis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; the crosslinking agent is liquid polybutadiene; the nucleating agent is high density polyethylene with a melt flow rate of 7g / 10min(190℃, 2.16kg).

[0133] The intermediate material is heated to 70℃, 1.3 parts by weight of crosslinking agent mixed with 0.2 parts by weight of molecular weight regulator is added and uniformly mixed, and post-absorption is carried out. The crosslinking agent is dicumyl peroxide, the molecular weight regulator is 2,4-diphenyl-4-methyl-1-pentene, the post-absorption temperature is 70℃, and the absorption time is 16h, to obtain a cable insulation material.

[0134] Comparative Example 5

[0135] Take 100 parts by weight of low density polyethylene, 0.2 parts by weight of antioxidant and 0.5 parts by weight of nucleating agent through the metering scale metering system mixed after automatic adding into double screw extruder, the temperature of the discharge port is controlled below 100℃, 0.2 parts by weight of crosslinking agent is put into the double screw through the liquid scale, the screw speed is set to 200rpm, the temperature of each zone of the double screw body is 100℃, 125℃, 135℃, 145℃, 155℃, 170℃, 180℃, 190℃, 195℃, 195℃, after mixing, homogenizing, filtering, extruding and granulating, the intermediate material is obtained. The melt flow rate of the low density polyethylene is 1.9g / 10min(190℃, 2.16kg); the antioxidant is 2,2'-thiobis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; the crosslinking agent is liquid polybutadiene; the nucleating agent is high density polyethylene with a melt flow rate of 7g / 10min(190℃, 2.16kg).

[0136] The intermediate material is heated to 70℃, 1.4 parts by weight of crosslinking agent mixed with 0.1 parts by weight of molecular weight regulator is added and uniformly mixed, and post-absorption is carried out. The crosslinking agent is dicumyl peroxide, the molecular weight regulator is 2,4-diphenyl-4-methyl-1-pentene, the post-absorption temperature is 70℃, the absorption time is 16h, and the cable insulation material is obtained.

[0137] Comparative Example 6

[0138] 100 parts by weight of low-density polyethylene, 0.2 parts by weight of antioxidant, and 0.5 parts by weight of nucleating agent are mixed by a metering scale metering system and then automatically added to a twin-screw extruder, and the temperature of the discharge port is controlled below 100℃. 0.2 parts by weight of a crosslinking aid is added to the twin-screw extruder by a liquid scale. The screw speed is set to 200 rpm, and the temperature of each zone of the twin-screw body is 90℃, 115℃, 130℃, 140℃, 155℃, 165℃, 175℃, 185℃, 185℃, and 185℃. After mixing, homogenizing, filtering, extruding, and granulating, the intermediate material is obtained. The low-density polyethylene has a melt flow rate of 1.9g / 10min (190℃, 2.16kg); the antioxidant is tetra[β-(3',5'-di-tert-butyl-4'-hydroxyphenyl) propionic acid] pentaerythritol ester; the crosslinking aid is liquid polybutadiene; and the nucleating agent is high-density polyethylene with a melt flow rate of 7g / 10min (190℃, 2.16kg).

[0139] The intermediate material is heated to 70℃, 1.0 parts by weight of crosslinking agent mixed with 1.2 parts by weight of molecular weight regulator is added and uniformly mixed, and post-absorption is carried out. The crosslinking agent is dicumyl peroxide, the molecular weight regulator is 2,4-diphenyl-4-methyl-1-pentene, the post-absorption temperature is 70℃, the absorption time is 16h, and the cable insulation material is obtained.

[0140] Comparative Example 7

[0141] Take 100 parts by weight of low density polyethylene, 0.2 parts by weight of antioxidant and 6 parts by weight of nucleating agent mixed by metering scale metering system after automatic addition to the twin screw extruder, the temperature of the discharge port is controlled below 100℃, 0.6 parts by weight of crosslinking agent is added into the twin screw by liquid scale. Set the screw speed to 200 rpm, the temperature of each zone of the twin screw body is 100℃, 125℃, 135℃, 145℃, 155℃, 170℃, 180℃, 190℃, 195℃, 195℃, after mixing, homogenizing, filtering, extruding and granulating, the intermediate material is obtained. The melt flow rate of the low density polyethylene is 1.9g / 10min (190℃, 2.16kg); the antioxidant is 2,2'-thiobis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; the crosslinking agent is liquid polybutadiene; the nucleating agent is high density polyethylene with a melt flow rate of 7g / 10min (190℃, 2.16kg).

[0142] Heat the intermediate material to 70℃, add 0.8 parts by weight of crosslinking agent mixed with 1.2 parts by weight of molecular weight regulator, and carry out post-absorption. The crosslinking agent is dicumyl peroxide, the molecular weight regulator is 2,4-diphenyl-4-methyl-1-pentene, the post-absorption temperature is 70℃, and the absorption time is 16h, to obtain the cable insulation material.

[0143] Performance test

[0144] It is particularly pointed out that the cable insulation material is a composition, which has excellent anti-scorching property and low by-products while ensuring that the conventional properties meet the standard requirements. A best balance between the properties is required to obtain a cable insulation material with excellent properties.

[0145] 1. Rheological property test

[0146] The rheological experiment was carried out by using a torque rheometer, the temperature was 140℃, the rotation speed was 45rpm, and the rheological time was 15min, and the results are shown in Figure 1 It should be noted that, since the rising amplitude of the torque curve of the cable insulation materials of examples 1-11 and comparative examples 3-4 is similar, the curve is fitted to a curve for more intuitive comparison.

[0147] It can be seen from Figure 1 that the rheological curve torque of examples 1-11, comparative examples 3-4 and 7 rises slowly, and the anti-scorching property is excellent. The rheological curve torque of comparative example 2 rises slightly faster than that of examples 1-11, and the anti-scorching property is slightly worse. The rheological curve torque of comparative examples 1 and 5-6 rises faster, and the anti-scorching property is poor.

[0148] 2. By-product content test

[0149] The by-product content of the cable insulation materials of Examples 1-11 and Comparative Examples 1-7 was tested by weight loss method, and the test method was as follows: take mg (5 g was used in the experiment, that is, m is 5) sample, crosslinking using a flat vulcanizing machine at 175℃, the sheeting process: preheating for 30 seconds, exhausting for 30 seconds, pressurizing to 20Mpa for 10 minutes, cooling, weighing its weight m1 (loss amount in the crosslinking process), placing it in a 70℃ air oven for 2 hours of degassing, weighing its weight m2, calculating, and the results are shown in Table 1 and Table 2 as follows:

[0150] Crosslinking by-product loss amount in the crosslinking process = (m-m1) / m x 100%

[0151] Total crosslinking by-product content = (m-m2) / m x 100%

[0152] Table 1: By-product content of examples

[0153]

[0154] Table 2: By-product content of comparative examples

[0155]

[0156] From Table 1 and Table 2, it can be seen that the introduction of crosslinking aids and molecular weight additives in Examples 1-11 and Comparative Examples 2-7 can reduce the amount of crosslinking agent added, thereby reducing the content of by-products; Comparative Example 1 is prepared by a more conventional method, and its by-product content is higher than that of Examples 1-11 and Comparative Examples 2-7.

[0157] 3. Electrical strength reliability

[0158] The electrical strength reliability of the examples and comparative examples was statistically analyzed by two-parameter Weibull distribution, the original data are shown in Table 3 and Table 4, and the results are shown in Figure 2 and Figure 3 (wherein, the scale parameter refers to the electrical strength at the cumulative failure probability of 63.2%, the greater the value, the greater the electrical strength; the shape parameter is a dimensionless characteristic parameter, which is related to the defect type causing breakdown, the degree of insulation deterioration, and the test conditions such as voltage and temperature).

[0159] The detection standard is as follows:

[0160] GB / T 1408.1-2016 Insulating materials - Determination of the electrical strength - Part 1: Test at power frequency (IEC 60243-1:2013, IDT)

[0161] Table 3: Electrical strength original data of examples (MV / m)

[0162]

[0163] Table 4: Raw data of electrical strength of comparative examples (MV / m)

[0164] Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Comparative example 6 Comparative example 7 1 36.45 38.43 40.65 35.87 40.81 40.83 40.30 2 34.39 42.24 42.71 39.71 40.98 39.09 42.67 3 40.19 39.33 39.81 39.03 39.98 36.44 41.45 4 37.35 39.08 37.85 39.33 41.51 41.58 42.43 5 38.31 39.80 39.52 36.45 42.71 40.19 39.95 6 37.75 38.11 41.69 34.23 38.46 37.77 43.33 7 37.20 38.03 38.92 38.75 39.81 36.79 41.79 8 38.42 39.70 41.86 34.39 40.49 40.10 37.87 9 36.75 38.14 42.19 37.77 36.81 40.12 38.54 10 41.45 41.51 38.14 40.19 39.29 38.60 42.39

[0165] From Figure 2 and Figure 3 It can be seen that the shape parameters and scale parameters of examples 1-11 and comparative examples 2-7 with nucleating agent are greater than that of comparative example 1 without nucleating agent, which indicates that the breakdown reliability of examples 1-11 and comparative examples 2-7 is higher than that of comparative example 1, and the electrical strength performance of the cable insulation material is superior.

[0166] In addition, comparative example 3 and comparative example 7 add more nucleating agent, it can be seen that when the content of nucleating agent is higher than 5 parts, the breakdown field strength of the cable insulation material cannot be further improved, and it is not conducive to later processing; comparative example 4 adds less nucleating agent, it can be seen that when the content of nucleating agent is less than 0.1 part, the breakdown field strength of the cable insulation material does not increase because of the addition of nucleating agent, and is equivalent to that of comparative example 1 without nucleating agent.

[0167] 3. Other properties

[0168] The other properties of the cable material were detected, and the test results are shown in Tables 5-7, and the specific detection standards are as follows:

[0169] GB / T 1040.1-2018 Determination of tensile properties of plastics - Part 1: General principles (ISO 527-1:2012, IDT)

[0170] GB / T 1040.3-2006 Determination of tensile properties of plastics - Part 3: Test conditions for films and sheets (ISO 527-3:1995, IDT)

[0171] GB / T 1409-2006 Recommended methods for measuring the permittivity and dissipation factor of electrical insulating materials at frequencies around power frequencies, at audio frequencies and at high frequencies (including meter wavelengths) (IEC 60250-1969, MOD)

[0172] GB / T 31838.2-2019 Solid insulating materials - Dielectric and resistive properties - Part 2: Resistive properties (DC method) Volume resistance and volume resistivity (IEC 62631-3-1:2016, IDT)

[0173] GB / T 2951.12-2008 Cable and optical fibre cables - Polymeric materials for insulation and sheaths - Test methods - Part 12: General test methods - Thermal ageing test methods (IEC 60811-1-2:1985, IDT)

[0174] GB / T 2951.21-2008 Cables and optical cables - Insulation and sheath materials - General test methods - Part 21: Special test methods for elastomer compounds - Resistance to ozone - Hot elongation test - Immersion in mineral oil (IEC 60811-2-1:2001, IDT)

[0175] Table 5

[0176]

[0177] Table 6

[0178]

[0179] Table 7: Other properties of the comparative examples

[0180]

[0181] From Tables 5-7, it can be concluded that the optimal addition amount of the cross-linking aid is 0-0.4 parts, and when the weight parts exceed 0.4 parts, the mechanical properties of the cable insulation material are lost more, and cannot meet the requirements of the cable insulation material, such as Comparative Example 2.

[0182] The introduction of the molecular weight regulator can improve the anti-scorching property of the cable insulation material, and the optimal addition amount is 0.2-1 parts by weight, and when the content of the molecular weight regulator is less than 0.2 parts by weight, the anti-scorching property of the cable insulation material is not obviously improved, such as Comparative Example 5; and when the content of the molecular weight regulator exceeds 1 parts by weight, the molecular weight regulator cannot be replaced by the cross-linking agent in equal amount, and the cross-linking degree of the cable insulation material cannot meet the standard requirements, such as Comparative Example 6.

[0183] In addition, the components of Comparative Example 7 are not within the scope of the present application, and the effects thereof are not as good as those of Examples 1-11.

[0184] In summary: the cable insulation material with anti-scorching property and low by-products of the present application is the balance among the antioxidant, the nucleating agent, the cross-linking aid, and the molecular weight regulator.

[0185] It should be noted that although the technical solutions of the present application are introduced with specific examples, those skilled in the art can understand that the present application should not be limited thereto.

[0186] Having described various embodiments of the application, it is to be understood that the above description is meant to be illustrative only and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art, without departing from the scope and spirit of the described embodiments. The choice of words in this document is intended to best explain the principles of the embodiments, the practical application, or technical improvement over the existing technology, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A cable insulation material, characterized by consisting of, by weight parts: low density polyethylene: 100 parts; nucleating agent: 0.1-5 parts; antioxidant: 0.1-0.4 parts; crosslinking agent: 1.0-1.9 parts; co-crosslinking agent: 0.1-0.4 parts; molecular weight regulator: 0.2-1.0 parts; the co-crosslinking agent includes liquid polybutadiene and / or triallyl isocyanurate; the molecular weight regulator includes 2,4-diphenyl-4-methyl-1-pentene; the nucleating agent includes one or a combination of both of high density polyethylene and nanosilica.

2. The cable insulation material of claim 1, wherein, The low density polyethylene has a density of 0.912 to 0.932 g / cm 3 ; and a melt flow rate at 190°C, 2.16 kg of 1.8 to 2.2 g / 10 min.

3. The cable insulation material according to claim 1 or 2, characterized in that, The high density polyethylene has a density of 0.940 to 0.976 g / cm 3 ; and a melt flow rate at 190°C, 2.16 kg of 6.5 to 10.0 g / 10 min.

4. The cable insulation material according to claim 1 or 2, characterized in that, the crosslinking agent includes a peroxide crosslinking agent; the antioxidant includes one or a combination of two or more of 2,2'-thiobis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tetra[β-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]pentaerythritol ester, and 4,4'-thiobis(6-tert-butyl-3-methylphenol).

5. The cable insulation material of claim 4, wherein, the crosslinking agent includes one or a combination of two or more of benzoyl peroxide, dicumyl peroxide, and di-tert-butyl peroxide.

6. A process for the preparation of a cable insulation material according to any one of claims 1 to 5, characterized in that, the method includes the steps of mixing and extruding, and granulating the components of the cable insulation material.

7. The production method according to claim 6, characterized in that, the method includes the steps of: mixing and extruding, and granulating the low density polyethylene, the nucleating agent, the antioxidant, and the co-crosslinking agent to obtain an intermediate material; mixing the intermediate material with the crosslinking agent and the molecular weight regulator, and then performing post-absorption to obtain the cable insulation material.

8. The production method according to claim 7, characterized by, the mixing, extruding, and granulating are performed using a twin-screw extruder; the post-absorption is performed at a temperature of 60-80°C for 16-24 hours.

9. The production method according to claim 8, characterized by, the twin-screw extruder is operated at a speed of 200-400 rpm, and the mixing is performed at a temperature of 85-205°C.

10. A cable, characterized by the cable insulation material according to any one of claims 1-5. the cable insulation material according to any one of claims 1-5.

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